"To ascend to the origin of things and speculate on the creation, is not the business of the natural philosopher. An humbler field is sufficient for him in the endeavor to discover, as far as our faculties will permit; what are these primary qualities impressed on matter, and to discover the spirit of the laws of nature"

“Self-respect is the cornerstone of all virtue.”

“Were I to pray for a taste which should stand me in stead under every variety of circumstances, and be a source of happiness and cheerfulness to me during life, and a shield against its ills, however things might go amiss and the world frown upon me, it would be a taste for reading... Give a man this taste, and the means of gratifying it, and you can hardly fail of making him a happy man; unless, indeed, you put into his hands a most perverse selection of books. You place him in contact with the best society in every period of history,—with the wisest, the wittiest, the tenderest, the bravest, and the purest characters who have adorned humanity. You make him a denizen of all nations, a contemporary of all ages. The world has been created for him.”

“Unfortunately... the philosophy of Aristotle laid it down as a principle, that the celestial motions were regulated by laws proper to themselves, and bearing no affinity to those which prevail on earth. By thus drawing a broad and impassable line of separation between celestial and terrestrial mechanics, it placed the former altogether out of the pale of experimental research, while it at the same time impeded the progress of the latter by the assumption of principles respecting natural and unnatural motions, hastily adopted from the most superficial and cursory and remark, undeserving even the name of observation. Astronomy therefore continued for ages a science of mere record, in which theory had no part, except in so far as it attempted to conciliate the inequalities of the celestial motions with that assumed law of uniform circular revolution which was alone considered consistent with the perfection of the heavenly mechanism.”

“God knows how ardently I wish I had ten lives”

“The question "cui bono" to what practical end and advantage do your researches tend? is one which the speculative philosopher who loves knowledge for its own sake, and enjoys, as a rational being should enjoy, the mere contemplation of harmonious and mutually dependent truths, can seldom hear without a sense of humiliation. He feels that there is a lofty and disinterested pleasure in his speculations which ought to exempt them from such questioning; communicating as they do to his own mind the purest happiness of which human nature is susceptible, and tending to the injury of no one, he might surely allege this as a sufficient and direct reply to those who, having themselves little capacity, and less relish for intellectual pursuits, are constantly repeating upon him this enquiry.”

“What God sends is welcome.”